This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Viruses are now unarguably considered essential components of marine ecosystems with regard to their natural abundance and their ecological implications. The interaction of viruses with microaggregates is, however, poorly documented despite the critical implications of microaggregates for the ocean biogeochemistry and the marine optical properties. Thus, the main goal of this project is to shed light on the interactions between viruses and microaggregates. One of the major studies of this project focuses on the impact of viral lysis on the dynamics of microaggregates. This study involves the use of virus [unreadable]host model systems isolated from the SIO-pier. The expected results will provide novel insights into our understanding of viral ecology and to a larger extend into the functioning of the ocean.